This is not just some faddish, interchangeable alternative to those long used and abused expressions 'Asia' or 'Asia Pacific'. Indo-Pacific is a viable definition of the broad region of principal strategic and economic importance to Australia, now and in all likelihood well into this century.

Indo-Pacific, or Indo-Pacific Asia, is also the best available shorthand for an emerging Asian maritime strategic system that encompasses both the Pacific and Indian oceans, defined in large part by the geographically expanding interests and reach of China and India and the continued strategic role and presence of the US.

But Australians are not alone in endorsing this changed way of speaking and thinking about Asia. Notably, the term has also entered US Secretary of State Hillary Clinton's lexicon, especially in describing the scope of the US-Australia alliance: 'We are also expanding our alliance with Australia from a Pacific partnership to an Indo-Pacific one'.

The Indo-Pacific is a concept that a few of us at the Lowy Institute have been exploring and promoting for some time.

We would certainly not claim to be the only think tank whose researchers have championed this term in the past few years, but it is fair to say that our work has anticipated and helped to inform a tangible shift in decision-makers' perspectives.

That said, it would be churlish not to note that I first encountered the term among some far-sighted Australian foreign service officials as far back as 2005, and that some Indian experts and policy practitioners such as Raja Mohan and Shyam Saran have been at the leading edge of the Indo-Pacific curve. This should not be surprising, given the concept's fit with a rising India's interests east of Malacca. Indeed, Wikipedia credits a 2007 Indian journal article with introducing the term to contemporary strategic policy debate.

There are some with mixed feelings about the Indo-Pacific idea, or about what the name actually means. Some scholars will no doubt challenge the view that the Indian and Pacific oceans, or maritime East and South Asia, can form a coherent strategic system. Certainly there will be some important security dynamics that remain principally concentrated in one or other of these subregions, such as Korean Peninsula tensions in North Asia or India-Pakistan relations on the subcontinent.

For now, the official Chinese position is to be circumspect if not suspicious about the Indo-Pacific, perhaps because it could be taken as legitimising India's role into China's Western Pacific neighbourhood, thus diluting a sense of the centrality of China in the Asian strategic order. Some Australian scholars also seem to associate the popularisation of Indo-Pacific with a China-balancing strategic agenda, even though they see academic merit in the term.

Yet there are powerful objective arguments for the integrity of the Indo-Pacific idea simply as a description of new geopolitical realities. Not least among these is the fact of China's and other East Asian nations' energy and trade reliance on Indian Ocean sea-lanes, a dependence that is set to deepen further, whatever success Beijing encounters in building continental transport corridors.

Indeed, when Chinese maritime trade with Africa and the Middle East is combined with its overwhelmingly important strategic and economic relations across the Pacific with the US, China is arguably the quintessential Indo-Pacific power. My colleagues Anthony Bubalo and Malcolm Cook have notably argued for a 'horizontal' definition of Asia to reflect growing economic and strategic linkages from the Western Pacific to the Middle East. In so doing, they seem to have recognised that the maritime dimension is likely to remain at least as important as the continental one, if not more so. This sounds not unlike the Indo-Pacific.

In any case, given Australia's unique geography as a continent bridging the Pacific and the Indian oceans at the southern edge of dynamic Asia, for this country at least the Indo-Pacific idea is here to stay. Let's hope it is reflected in the Asian Century White Paper shortly to be released by the Australian Government. Oh, and for those interested in the long debate about Australia's elusive geopolitical and socio-cultural identity, here at last is a definition of Asia that automatically includes Australia. And that, I admit, is another reason I like it.